Radeon HD 4750 vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory is set to run at a speed of 1125 MHz on this particular model. It features 640 SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4750		75 Watts
Radeon HD 7770		80 Watts
	Difference: 5 Watts (7%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7770 should be quite a bit faster than the Radeon HD 4750 in general. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 20800 (41%)

Texel Rate

The Radeon HD 7770 should be quite a bit (about 71%) more effective at texture filtering than the Radeon HD 4750. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 16640 (71%)

Pixel Rate

The Radeon HD 7770 will be quite a bit (about 37%) better at AA than the Radeon HD 4750, and will be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4750		11680 Mpixels/sec
	Difference: 4320 (37%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of data (measured in megabytes per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory speed. If it uses DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.